On top of this sub-sea problem is
the fact that ocean water is about as
corrosive as many acids, so ROVs must
use corrosion-resistant materials in
their construction. Also adding to the
hostility of ocean depths is the lack of
light which finally disappears at about
200 meters down. So, deep-diving
ROVs must carry their own light
sources if the operators intend to see
and record what is below.

US Navy CURV ROVs
to the Rescue in the
‘60s and ‘70s

Before delving into today’s
advanced ROVs, I would like to take a
look back at the past to a series of
the first fully functional/remotely
operated underwater vehicles: the US
Navy CURV I (shown in Figure 3) to
CURV III (and even to CURV 21).

The impetus for the development
of the remotely operated CURV in the
early 1960s was to recover Navy
torpedoes after testing. This normally
required a team of specially-trained
divers and their support team, unique
ships outfitted with recompression
chambers and cranes, and a team of
doctors.

Needless to say,
the task was
dangerous, and even
more so as recovery
depths increased over
the years. Divers were
limited to much
shallower depths, so a
more maneuverable
unmanned vehicle was required. In
the mid-1960s, the Navy developed
the CURV cable-controlled Underwater
Recovery Vehicle to perform the
difficult (but essential) weapons
recovery role.

These vehicles accomplished some
amazing rescues that were every bit
as daring and life-saving as the Apollo
13 rescue during April 11-17th, 1970.
In January 1966 near the south coast
of Spain, an Air Force B- 52 bomber
collided with a KC-135 refueling
tanker. The resulting crash scattered
debris and five 70 kiloton hydrogen
bombs over the Spanish coast near
the town of Palomares. Four of the
nuclear bombs were recovered on
land but the fifth was lost in the
depths of the Mediterranean Sea due
to a partially deployed parachute that
caused the winds to carry the bomb
out to the sea.

Nuclear weapons in a United
States military plane that crossed
Spain’s sovereign territory and then
crashed was not something that the
US wanted amidst the cold war era,
but the media soon exposed the
mess. Initial attempts in recovery of
the bomb over a period of three
months only allowed it to become
more embedded in the sea floor and
at a deeper depth.

The Navy decided to secure the
services of the Woods Hole
Oceanographic Institution’s manned
submersible, Alvin to search for the
bomb and then use CURV to assist the
sub. Shown in Figure 4, Alvin located
the missing atomic bomb shown in
Figure 5 at a depth of 2,850 feet.

An interesting fact about Alvin is
that is actually accidentally sank itself
in 1968, when two cables snapped
while it was being hoisted aboard its
tender ship; the manned pilot’s
sphere’s hatch had been left open.